[Zeke]

Well, since he blew it on the instructions, I'll offer my, and slightly different solution:

Pour 3 into the 5 and mark the line.

Fill the 5 with another full 3 which should leave one left in the 3.

pour out of the five until the line is reached and pour in the leftover one gal. in the 3 gal. jug.

Just a backwards way of Red's solution involving a mark. If you didn't have a way of making the mark (in the movie there were two people, so I figured one of them would hold the mark), Red's solution is better. It's better all the way around, just makes one fill the three gal. 3 times whereas my solution requires only 2 fills. Remember, the action needed to be done in the movie within a time frame.

Does anyone remember how Bruce and Sam did it?